A city police officer is now on trial for beating up a 25-year-old Barrie man over a broken Christmas ornament at the Bayfield Mall.

Const. Jason Nevill is charged with assault causing bodily harm, fabricating the evidence against the victim and obstruction of justice.

The incident was caught on the mall security video which shows Nevill repeatedly punching the victim, Jason Stern, in the head as he lay face down on the pavement, pinned by two mall security officers.

The video, which was played in court, shows the beating going on for several minutes.

Twice, Stern appears to have gone limp and unconscious, but still the officer can be seen punching him in the head.

“I didn’t know why I was being beaten — I kept pleading with him, ‘Stop, stop, I’m a good person’,” Stern said on the witness stand, dressed in a suit and tie.

“Then I blacked out.”

Stern said he came to and the punching was still going on.

The entire incident began with the video showing Stern walking through Bayfield Mall with his girlfriend and another couple after a midnight game of bowling when suddenly his friend, Simon, playfully reached up and took a swipe at a Christmas ornament, causing it to break.

The foursome then exited the mall, but Stern returned because he forgot his wallet.

He was met at the door by two security officers who asked him to remain until police arrived on scene. Stern is seen waiting patiently with the two security officers, not knowing he was facing any trouble.

As Nevill approaches, the two can be seen talking when, out of the blue, Nevill attacks Stern and wrestles him to the ground.

“He asked me what my friend’s name was,” explained Stern. “I didn’t want to tell him. I figured the worst that could happen was I would have to pay for the Christmas ornament.”

Court heard how Nevill later told police that Stern had attacked him first by kneeing him in the groin, and that he only punched Stern twice. However, the video shows Nevill delivering about a dozen blows to Stern’s head without ever being attacked.

“I was terrified. I was so confused,” said Stern, noting he has never been in trouble with police and has never been in a fight. “I will never know, to this day, why it happened.”

Stern said he was thrown in the back of the police cruiser with his hands cuffed behind his back. The officer then instructed the security guards to get a pail of water and wash away a pool of blood that was left on the pavement.

Stern was then taken to hospital and ended up with a concussion, facial bruises, stitches to his head, black eyes and bruises on his knees. He said while waiting in the examination room, he was confused.

“I felt fuzzy and woozy,” he said. “I couldn’t piece together what was going on.”

Later at the police station, Stern was informed he was being charged.

“I was so scared,” Stern said. “I I had never been in trouble before. I asked the officer what I should do and he told me to plead guilty.”